Given the data: K= $100, h = $1, r= (20,30, 50, 10, 20, 30). Determine the optimal order policy and the cost (including set-up and holding costs) using the following heuristic lot-sizing scheme. What is the optimal order policy based on least unit cost heuristic? Select the closest answer: O a.r = (50, 0, 80, 30, 0, 0) O b.r = (100, 0, 0, 60, 0, 0) O c. r = (50, 0, 80, 0, 0, 30) O d.r = (50, 0, 80, 0, 30, 0)